SEM not only allows to see smaller things - it can also have larger depth of focus (so we can see things more in "3d") and shows texture/material differently. Let's look at few select chips of the past 2 years.
After dreaming for many years about a cleaner way of chip decapsulation, I finally got my hands on a MOPA fiber laser. But like many things in this life, it apparently is more complicated than it seems. I went through ~20 chips trying to find pulse energy threshold that still eats through plastic, but keeps microchip alive. Unfortunately, at least for glass-filled plastic, I don't see any opening in the process window.